(The SIMH makefile expects the top level "display" directory to be a
symlink to (or the contents of) the "xy" directory...)

Another CVS module history/pdp1 contains my version of the "macro1" PDP-1 assembler, which can
assemble spacewar, my (nearly pristine) version of PDP-1 DDT, and a
version of DECUS MACRO! The module contains source for ddt, spacewar,
PDP-1 lisp (all used as regression tests), and (very simple) source
for the munch.rim file included in the above tarball.